Multi-conductor electric cables

ABSTRACT

A multi-conductor cable for forming a cable harness, for instance for use in automobiles or aircraft, comprises at least one length of tape cable enclosed in a heat-shrunk tubular sheath of insulating material. At least one branch length of tape cable is electrically connected to the length of tape cable, or to at least one of the lengths of tape cable, at at least one of a number of longitudinally spaced locations, the free end of the branch length protruding from the tubular sheath. An individually insulated conductor and/or a twin or multi-conductor insulated cable may also be enclosed within the tubular sheath. In a cable harness incorporating the multi-conductor cable at least some of the conductors of the length or lengths of tape cable and/or of the branch length or lengths of tape cable are electrically connected to insulated terminal leads.

United States Patent Lawrenson [54] MULTI-CONDUCTOR ELECTRIC CABLES [72]Inventor: Thomas Lawrenson, Helsby, via

Warrington, England [7 3] Assignee: British Insulated Callenders CablesLimited, London, England 22 Filed: Feb. 29, 1972 21] Appl.No.:230,325

[30] Foreign Application Priority Data March 3, 1971 Great Britain..5,905/7l [52] US. Cl. ..l74/72 A, 156/51, 174/113 R, 174/115, 174/117F[51] Int. Cl. ..H0lb 7/08 [58] Field of Search.....174/7l R, 72 R, 72 A,72 TR, 174/84 R, 113 R, 115, 117 R, 117 F, 117 FF, I DIG. 8, 110 V;156/51, 52, 53, 54, 55, 56

[56] References Cited UNITED STATES PATENTS 3,634,808 l/1972 Morrison..174/1 17 FF 3,627,903 12/1971 Plummer ..174/l17 F 3,524,921 8/1970Wolf ..l74/117 FF 3,079,458 2/ 1963 Hedstrom ..l74/l 17 FF X Oct. 24,1972 2,299,140 10/1942 Hanson ..l74/72 A FOREIGN PATENTS OR APPLICATIONS765,705 1/1957 Great Britain ..l74/DlG. 8

Primary ExaminerLewis H. Myers Assistant Examiner-A. T. GrimleyAttorney-Eugene F. Buell et al.

[57] ABSTRACT A multi-conductor cable for forming a cable harness, forinstance for use in automobiles or aircraft, comprises at least onelength of tape cable enclosed in a heat-shrunk tubular sheath ofinsulating material. At least one branch length of tape cable iselectrically connected to the length of tape cable, or to at least3,048,651 8/1962 Howard et a1. ..'.174/DIG. 8 30 Claims,4Drawing Figuresa Pr 21 I ;1:]

P'A'TENTED um 24 1912 sum 2 0F 2 1 MULTI-CONDUCTORELECTRIC CABLES Thisinvention relates to multi-conductor electric cables and especially, butnot exclusively, to cables forming part of a cable assembly of the kindknown as a cable harness, for use for example in motor vehicles andaircraft, in which a multi-conductor unit or two or more multi-conductorunits is or are encased in a common protective. sheath.

Objects of the invention are to provide an improved multi-conductorcable suitable foruse in forming a cable harness and to provide animproved method of making the multi-conductor cable. The invention alsoincludes an improved cable harness incorporating the improvedmulti-conductor cable.

In accordance with the invention the improved multi-conductor cablecomprises at least one length of tape cable enclosed in a heat-shrunktubular sheath of insulating material and, electrically connected tosaid length or at least one of said lengths of tape cable at onelocation or at each of a number of longitudinally spaced locations, atleast one otherlength of tape, cable (hereinafter referred to as abranch length of tape cable) whose free end protrudes from the tubularsheath.

The term tape cable as used herein means cable comprising two or moreconductors arranged side by side and embedded in a flexible tape ofinsulating material of a thickness small in comparison with its width.The form of tape cable preferred for use in accordance with the presentinventionis that known as a ribbon cable, in which each conductor is ametal ribbon arranged with its major transverse axis parallel to themajor transverse axis of the cable.

A heat-shrunk tubular sheath is a sheath formed from thermallyshrinkable insulating tubing which is caused to shrink by theapplication of heat and grip the length or lengths of tape cable whichit encloses. Such a heat-shrunk tubular sheath is resistant toweatherand mechanical abrasion and has a relatively high tensile strength. A

At least one branch length of an individually insulated conductor,preferably of substantially circular cross-section, is electricallyconnected to said length or at least one of said lengths of tape cableat one location or at each of a number of longitudinally spacedlocations with its free end protruding from the tubular sheath.

In addition to comprising, as an essential element, at least one lengthof tape cable, the multi-conductor cable may also include one or morethan one in dividually insulated conductor of circular or non-circularcross-section and/or one or more than one twin or multi-conductorinsulated cable enclosed within the tubular sheath. The or eachindividually insulated conductor and/or each conductor of the or eachtwin or multi-conductor insulated cable preferably has a greater loadcarrying capacity than the conductors of the length or lengths of tapecable.

The heat-shrunk tubular sheath may comprise a single tube of insulatingmaterial extending over substantially the whole length of thecable but,with a view to accommodating for the or each branch length of tapecable, the tubular sheath is preferably built up of several individuallengths of insulating tubing connected end to end. Connection betweentwo such adjoining individual lengths of tubing may be effected byarranging for each individual length of tubing to overlap or beoverlapped by-its adjoining individual length or lengths of tubing butpreferably it is effected by means of a short length of tube thatoverlaps or is overlapped by the neighboring end of each individuallength of tubing which it interconnects. The overlaps between individuallengths of tubing, or between individual lengths of tubing and shortconnecting lengths of tube,

. arepreferably bonded by an adhesive.

Where the heat-shrunk tubular sheathis built up of several individuallengths of insulating tubing the or a branch length of tape cablepreferably protrudes lengthwise along the cablefrorn between theneighboring ends of two adjoining individual lengths of tubing. At leasta major part of the branch length of tape cable, or. of each of some orall of the branch lengths of tape cable, is preferably itself enclosedin a heat-shrunk tubular sheath of insulating material which may extendbeneath the short length of tube overlapping or overlapped by theneighboring end of such individual length of tubing which itinterconnects or beneath the overlapping end of one of two adjoiningindividual lengths of tubing.

Where the multi-conductor cable comprises two or more lengths of tapecable, the lengths are preferably assembled face to face so that thecable is of a flatten ed cross-section and the branch lengths of tapecable, and of individually insulated conductor when present, preferablyprotrude from one or both of the wider faces of the sheath. Although itis preferred to arrange for each of the branch lengths of tape cable tohave the same number of conductors as the length of tape cable to whichit is electrically connected, each of some or all of the branch lengthsof tape cable may have fewer conductors than the associated lengthoftape cable.

According to another aspect of the invention there is provided animproved cable harness comprising at least in part a multi-conductorcable in accordance with the present invention, some or allof theconductors of the length or lengths of tape cable and/or of the branchlength or lengths of tape cable being electrically connected toinsulated terminal leads, preferably of substantially circular crosssection.

Preferably the insulation of each terminal lead is of a distinctivecolor or carries marking for identifying the function 'of the cableconductor to which it is connected.

The invention also includes animproved method of making amulti-conductor cable,-which method comprises electrically connecting toa length of tape cable or to at least one of a number of lengths of tapecable at one location or at each of a number of longitudinally spacedlocations at least one branch length of tape cable; applying over thelength or lengths of tape cable a tubular sheath of heat-shrinkableinsulating material; arranging for the free end of the or each branchlength of tape cable to protrude from the sheath; and subjecting thesheathed'assembly to sufficient heat to cause the tubular sheath toshrink and grip the length or lengths of tape cable.

Preferably two'or more. lengths of tape cable are arranged face to faceto form an assembly of flattened cross-section and the or each branchlength of tape cable is connected to one or more of the lengths of tapecable in such a way that its free end protrudes from a wider side of thesheath. Y

The tubular sheath may be applied to the length or lengths of tape cableby drawing a single tube of heatshrinkable insulating material over theassembly and arranging for the or each branch length of tape cable toprotrude through a slit in the tube but it is preferably formed byapplying over the assembly several individual lengths of insulating tubearranged end to end with the ends of adjoining individual lengths oftubing overlapping one another, or overlapping or being overlapped bythe ends of a short length of insulating tubing, the or each branchlength of tape cable being arranged to protrude from between overlappingends of adjoining lengths of tubing. Preferably the overlapping ends ofthe lengths of tubing are secured together by adhesive, which ispreferably a heat-sensitive adhesive that is activated by the heatapplied to heat shrink the sheath. The adhesive may be applied to theunderlying of the two overlapping ends of adjoining lengths of tubing asa tape or in a liquid form. In both cases the tubular sheath ispreferably of plasticized polyvinyl chloride.

When electrically connecting a branch length of tape cable to a lengthof tape cable the branch length may be arranged to lie substantiallyparallel to the length of tape cable and to be electrically connectedthereto, for instance by spot welding or by an insulation-piercingcrimp, adjacent to one of its ends. Preferably to strengthen theelectrical connection between a branch length of tape cable and theassociated length of tape cable in order to reduce the risk of damage tothe connection when the branch length is manipulated, after the branchlength has been electrically connected to the length of tape cable it isfolded at least partially around the length or lengths of tape cablebefore it is arranged to extend lengthwise with respect to the length orlengths of tape cable. In one method of so strengthening an electricalconnection the branch length of tape cable is folded adjacent theconnection about. a line extending at approximately 45 to the axis ofthe cable, is wrapped at least partially around the length or lengths oftape cable, and is then folded about a line substantially parallel tothe first fold in such a way that the branch length of tape cableextends lengthwise along the length or lengths of tape cable.

Preferably the part of the or each branch length or group of branchlengths of tape cable protruding from the sheath has a tube ofheat-shrinkable insulating material applied over it before heat isapplied to the sheath and tube or tubes to cause them to shrink.

Where an insulated terminal lead is to be connected electrically to anend of a conductor of a length of tape cable or to a branch length oftape cable preferably an exposed end of the lead is connected to theconductor at a point spaced from the extreme end of the conductor,heat-sensitive adhesive is applied over the end of the tape cable andthe overlying insulated terminal lead, a length of heat-shrinkabletubing is applied over the end of the sheath, the connection so formedand the applied adhesive, and heat is applied to shrink the tubing andcause the adhesive to activate and form an effective moisture-tight sealat the end of the sheath.

The invention will be further illustrated by a description, by way ofexample, of a preferred form of cable harness and of the preferredmethods of connecting a branch cable and insulated terminal lead to amulticonductor cable to form the cable harness with reference to theaccompanying drawings, in which FIG. I is a diagrammatic representationof the cable harness,

FIG. 2 is a perspective fragrnental view of the multiconductor cable ofthe harness,

FIG. 3 (a to d) illustrates the stages in the method of connecting abranch length of tape cable to the cable shown in FIG. 2, and

FIG. 4 is a perspective fragrnental view of an end of the cable shown inFIG. 2 with insulated terminal leads connected to it.

Referring to FIGS. 1 and 2 the harness includes a multi-conductor cablecomprising three tape cables 1, 2 and 3 assembled face to face and anindividually insulated conductor 4, the cables and conductors beingenclosed in a heat shrunk tubular sheath 5 of plasticized polyvinylchloride. The sheath 5 is built up of several lengths of heat shrunktubing arranged end to end. Electrically connected to the conductors ofthe tape cables l and 2, respectively, at longitudinally spacedlocations along the length of the cable and protruding betweenneighboring ends of adjoining lengths of heat shrunk tubing are branchlengths 6 and 7 of tape cable,

each branch length 6, 7 having a heat shrunk tubular sheath 8, 9comprising several lengths of plasticized polyvinyl chloride tubingarranged end to end. Heat shrunk sleeves 10 of plasticized polyvinylchloride overlie the electrical connections between the cable and branchlengths 6, 7 and the neighboring ends of the lengths of heat-shrunksheath 5.

Between the longitudinally spaced locations at which the branch lengths6 and 7 are connected a branch length 11 of an individually insulatedconductor of substantially circular cross-section passes betweenneighboring ends of adjoining lengths of heat shrunk tubing of thesheath 5 and its conductor is electrically connected to one of theconductors of tape cable 2 by an insulation-piercing crimp. A branchlength 12 of a similar individually insulated conductor of substantiallycircular cross-section passes between neighboring ends of adjoininglengths of heat shrunk tubing of the sheath 9 and its conductor iselectrically connected to one of the conductors of the branch length 7of tape cable by an insulation-piercing crimp. The electricalconnections between the insulated conductors 11 and 12 and the cable andbranch length 7 are each enclosed in a heat shrunk sleeve 14 ofplasticized polyvinyl chloride.

At one end of the multi-conductor cable insulated terminal leads 16,each of substantially circular crosssection, are electrically connectedto the conductors of tape cable 3 by insulation-piercing crimps, theconnections and the protruding end of the insulated conductor 4 beingenclosed in a heat shrunk sleeve 17 of plasticized polyvinyl chloride.Insulated terminal leads 18, each of substantially circularcross-section, are electrically connected to the conductors of thebranch length 7 of tape cable at its free end by insulation-piercingcrimps, these electrical connections being enclosed in a heat shrunksleeve 17 of plasticized polyvinyl chloride.

As will be seen on referring to FIG. 3 (a to d) in electricallyconnecting the conductors of a branch length 6 of tape cable to theconductors of a tape 1 of a multiconductor cable in accordance with theinvention, the branch length is arranged to overlie and extendsubstantially parallel to the tape cable and the conductors of thebranch length are electrically connected to the underlying conductors ofthe tape cable by insulationpiercing crimps. The branch length '6 oftape cable is folded adjacent the connections about a line extending atapproximately 45 tothe axis of the cable (FIG. 3a) and the branch lengthis then wrapped partially around the lengths of tape cable of themulti-conductor cable (FIG. 3b). The branch length 6 is then foldedabout a line substantially parallel but in the opposite sense to thefirst fold in such a waythat the branch length extends lengthwise alongthe lengths of tape cable (FIG. 30). A heat shrinkable sleeve 10 ofplasticizedpolyvinyl chloride, that has previously been applied to themulticonductor cable,'is now drawn over the electrical connectionsbetween the branch length 6 and tape cable '1 so that is overlaps theneighboring ends of the lengths 5 of polyvinyl chloride tubing of thesheath 5 and the sheath 8 of the branch length to which heat sensitiveadhesive has previously been applied and heat is applied to the sheathsand sleeve to causethem to shrink (FIG. 3d) and to cause the resin toactivate and form a moisture-tight seal.

As will be seen on referring to FIG. 4, in terminating an end of themulti-conductor cable individually insulated terminal leads 16 ofsubstantially circular crosssection are arranged to overlie the endofthe tape cable 3 and are'each electrically connected to a conductor ofthe tape cable ata point spaced from its extreme end by aninsulation-piercing crimp. Heat-sensitiveadhesive is Y applied overthe-end of the tape cable 3 and theoverlying insulated terminal leadsand a heat shrinkable sleeve 17 of plasticized polyvinyl chloride isapplied over the end of the sheath 5,the connections so formed and theapplied adhesive. l-leat is appliedto shrink the sleeve 17 and causetheadhesive toactivate and form an effective moisture-tight sealattheend of the sheath.

In an alternative method of terminating anendofthe 4. A multi-conductorcable as claimed in claim 1 which comprises at least two lengths of tapecable, wherein the lengths are assembled face tofaceso that the cable isof aflattened cross-sectionand the branch lengths of tape cable protrudefrom at least one of the wider faces of the sheath.

5. A multi-conductor cable as claimed in claim 1, wherein the or eachbranch length of tapecable has the same number of conductors as thelength of tape cable to which it is electricallyconnected.

6. A multi-conductor cable ,as claimed in claim 1, wherein'the tubularsheath is built up of .several individual lengths of insulating tubingconnectedend to end.

7. A multi-conductor cable .as,.,claimed in claim 6, wherein connectionbetween two adjoining individual lengths of tubing is effected by .avshort length .of'tube that overlaps the neighboring end of eachindividual length of tubing which it interconnects.

8. A multi-conductor cable as claimed in claim 7, wherein overlapsbetween individual lengthsof tubing and short connecting lengthsof tubeare bonded by an adhesive.

9; A multi-conductor cable as claimed in claim 6,

' wherein each individual length of tubing at one of its multi-conductorcable of the presentinvention to-form a cable harness a multi-pinconnector is directlyconnected to conductors of the length ,or lengthsof .tape cable, preferably using insulation-piercing electricalconnectors of a known kind. 6

The cable harness of the present invention is neat, compact andsubstantially water-tightand, by virtue of its construction, can bereadily secured to the bodywork of a motor vehicle or an aircraft.

What I claim as my invention is:

1. A multi-conductor cable comprisingat least one length of tape cableenclosed in a heat-shrunk tubular sheath of insulating material and,electrically connected to said length or at least one of said lengths oftape cable at at least one of a number of longitudinally spacedlocations, at least one branch lengthcf tape cable whose free endprotrudes from the tubular sheath. v

e 2. A multi-conductor cable as claimed in claim 1, wherein at least amajor part of the branch length of tape cable, or of at least one of thebranch lengths of tape cable, is enclosed in a heat-shrunktubular sheathof insulating material.

3. A multi-conductor cable as claimed in claim 1, wherein at least onebranch length of an individually insulated conductor is electricallyconnected to said length or at least one of said lengths of tape cableat at least one of a number of longitudinally spaced locations with itsfree end protruding from the tubular sheath.

ends overlaps or is overlapped by its adjoining individual length oftubing.

'10. A multi-conductor cable as claimed in claim 9, wherein overlapsbetween individual lengths of tubing are'bonded by an adhesive.

11. A multi-conductor cable as claimed in claim 6, wherein at least amajor part of the branch length of tape cable, or of at least one of.the branch lengths of tape cable, is itself enclosed in aheat-shrunktubular sheath of insulating material which extends beneaththe short length of tube overlappingand interconnecting the neighboringends of two individual lengths of tubing.

,12. A multi-conductorcable as claimed in claim 6, wherein the ora'branch length-of tape cableprotrudes lengthwise alongthe cable frombetween the neighboring ends of two adjoining individual lengths oftubing.

13. Armulti-conductor cablecomprising at least one length of tape cableenclosed in aheat-shrunk tubular sheath of insulating material, at leastone-of the group consisting of individually insulated conductors, twinconductor insulated cables .and multi-conductor insulated cablesenclosed within said tubular sheath and, electrically connected to saidlength or at least one of said lengths of tape cable at at leastone of.a number of longitudinally spaced locations, at least one branch lengthof tape cable whose free end protrudes from the tubular sheath.

14..A multi-conductor cable as claimed in claim 13,

' whereinthe or each conductorof the individually insulated conductor,twin or multi-conductor insulated cable has a greater loadcarryingcapacity than the conductors of the tape cable.

15. A cable harness comprising at least in part a multi-conductor cablecomprising at least one length of tape cable enclosed in a heat-shrunktubular sheath of insulating material and, electrically connected tosaid length or at leastone of said lengths of tape cable at at least oneof a number of longitudinally spaced loca- .tions, at least one branchlength of tape cable whose free end protrudes from the tubular sheath,at least some of the conductors of the tape cables being electricallyconnected to insulated terminal leads.

16. A cable harness as claimed in claim 15, wherein the connectionsbetween the insulated terminal leads and the conductors to which theyare connected are enclosed in a length of heat shrunk tubing ofinsulating material bonded to the tubular sheath and to the insulationof the terminal leads to form an efiective moisturetight seal at the endof the sheath.

17. A cable harness as claimed in claim 15, wherein the insulation ofeach terminal lead carries a distinctive color for identifying thefunction of the cable conductor to which it is connected.

18. A cable harness as claimed in claim 15, wherein each terminal leadis of substantially circular cross-section.

19. A method of making a multi-conductor cable which compriseselectrically connecting to at least one length of tape cable at at leastone of a number of longitudinally spaced locations at least one branchlength of tape cable; applying over the length or lengths of tape cablea tubular sheath of heat-shrinkable insulating material; arranging forthe free end of the or each branch length of tape 'cable to protrudefrom the sheath; and subjecting the sheathed assembly to sufficient heatto cause the tubular sheath to shrink and grip the length or lengths oftape cable.

20. A method as claimed in claim 19, wherein the tubular sheath isapplied to the length or lengths of tape cable by drawing a single tubeof heat-shrinkable insulating material over the assembly and arrangingfor the or each branch length of tape cable to protrude through a slitin the tube.

21. A method as claimed in claim 19, wherein the tubular sheath isformed by applying over the length or lengths of tape cable severalindividual lengths of tube of heat-shrinkable insulating material,arranged end to end with the ends of adjoining individual lengths oftubing overlapping one another, and arranging for the free end of the oreach branch length of tape cable to protrude from between overlappingends of adjoining lengths of tubing. I

22. A method as claimed in claim 19, wherein at least two lengths oftape cable are arranged face to face to form an assembly of flattenedcross-section and the or each branch length of tape cable is connectedto at least one of the lengths of tape cable in such a way that its freeend protrudes from a wider side of the sheath.

23. A method as claimed in claim 19, wherein the or each branch lengthof tape cable is arranged to lie substantially parallel to the length oftape cable to which it is to be connected and the branch length iselectrically connected thereto adjacent to one end of the branch 8length.

24. A method as claimed in claim 23, wherein after the branch length hasbeen electrically connected to the length of tape cable it is folded atleast partially around the length or lengths of tape cable before it isarranged to extend lengthwise with respect to the multi-conductor cable.

. 25. A method as claimed in claim 19, wherein after the branch lengthhas been electrically connected to the length of tape cable it is foldedadjacent the conlli fis fih e bif a%i 28 i l i galtiall; around thelength or lengths of tape cable, and is then folded about a linesubstantially parallel to the first fold in such a way that the branchlength of tape cable extends lengthwise along the multi-conductor cable.

26. A method as claimed in claim 19, wherein the part of the or eachbranch length of tape cable protruding from the sheath has a tube ofheat-shrinkable insulating material applied over it before heat isapplied to the sheath and tube to cause them to shrink.

27. A method as claimed in claim 19, wherein a cable harness is formedby electrically connecting an insulated terminal lead to a conductor ofa length of tape cable at a point spaced from the extreme end of theconductor; applying a heat-sensitive adhesive over the end of the tapecable and the overlying insulated terminal lead; applying a length ofheat-shrinkable tubing over the end of the sheath, the connection soformed and the applied adhesive; and applying heat to shrink the tubingand cause the adhesive to activate and form an effective moisture-tightseal at the end of the sheath.

28. A method of making a multi-conductor cable which compriseselectrically connecting to at least one length of tape cable at at leastone of a number of longitudinally spaced locations at least one branchlength of tape cable; applying over the length or lengths of tape cableseveral individual lengths of tube of heatshrinkable insulatingmaterial, arranged end to end with the ends of adjoining individuallengths of tubing being overlapped by the ends of a short length oftubing of heat-shrinkable insulating material to form a tubular sheath;arranging for the free ends of the or each branch length of tape cableto protrude from between overlapping ends of adjoining lengths oftubing; and subjecting the sheathed assembly to sufficient heat to causethe tubular sheath to shrink and grip the length or lengths of tapecable.

29. A method as claimed in claim 28, wherein the overlapping ends ofadjoining lengths of tubing are secured together by adhesive.

34 A method as claimed in claim 29, wherein the adhesive is aheat-sensitive adhesive that is activated by the heat applied to heatshrink the sheath.

1. A multi-conductor cable comprising at least one length of tape cableenclosed in a heat-shrunk tubular sheath of insulating material and,electrically connected to said length or at least one of said lengths oftape cable at at least one of a number of longitudinally spacedlocations, at least one branch length of tape cable whose free endprotrudes from the tubular sheath.
 2. A multi-conductor cable as claimedin claim 1, wherein at least a major part of the branch length of tapecable, or of at least one of the branch lengths of tape cable, isenclosed in a heat-shrunk tubular sheath of insulating material.
 3. Amulti-conductor cable as claimed in claim 1, wherein at least one branchlength of an individually insulated conductor is electrically connectedto said length or at least one of said lengths of tape cable at at leastone of a number of longitudinally spaced locations with its free endprotruding from the tubular sheath.
 4. A multi-conductor cable asclaimed in claim 1 which comprises at least two lengths of tape cable,wherein the lengths are assembled face to face so that the cable is of aflattened cross-section and the branch lengths of tape cable protrudefrom at least one of the wider faces of the sheath.
 5. A multi-conductorcable as claimed in claim 1, wherein the or each branch length of tapecable has the same number of conductors as the length of tape cable towhich it is electrically connected.
 6. A multi-conductor cable asclaimed in claim 1, wherein the tubular sheath is built up of severalindividual lengths of insulating tubing connected end to end.
 7. Amulti-conductor cable as claimed in claim 6, wherein connection betweentwo adjoining individual lengths of tubing is effected by a short lengthof tube that overlaps the neighboring end of each individual length oftubing which it interconnects.
 8. A multi-conductor cable as claimed inclaim 7, wherein overlaps between individual lengths of tubing and shortconnecting lengths of tube are bonded by an adhesive.
 9. Amulti-conductor cable as claimed in claim 6, wherein each individuallength of tubing at one of its ends overlaps or is overlapped by itsadjoining indiVidual length of tubing.
 10. A multi-conductor cable asclaimed in claim 9, wherein overlaps between individual lengths oftubing are bonded by an adhesive.
 11. A multi-conductor cable as claimedin claim 6, wherein at least a major part of the branch length of tapecable, or of at least one of the branch lengths of tape cable, is itselfenclosed in a heat-shrunk tubular sheath of insulating material whichextends beneath the short length of tube overlapping and interconnectingthe neighboring ends of two individual lengths of tubing.
 12. Amulti-conductor cable as claimed in claim 6, wherein the or a branchlength of tape cable protrudes lengthwise along the cable from betweenthe neighboring ends of two adjoining individual lengths of tubing. 13.A multi-conductor cable comprising at least one length of tape cableenclosed in a heat-shrunk tubular sheath of insulating material, atleast one of the group consisting of individually insulated conductors,twin conductor insulated cables and multi-conductor insulated cablesenclosed within said tubular sheath and, electrically connected to saidlength or at least one of said lengths of tape cable at at least one ofa number of longitudinally spaced locations, at least one branch lengthof tape cable whose free end protrudes from the tubular sheath.
 14. Amulti-conductor cable as claimed in claim 13, wherein the or eachconductor of the individually insulated conductor, twin ormulti-conductor insulated cable has a greater load carrying capacitythan the conductors of the tape cable.
 15. A cable harness comprising atleast in part a multi-conductor cable comprising at least one length oftape cable enclosed in a heat-shrunk tubular sheath of insulatingmaterial and, electrically connected to said length or at least one ofsaid lengths of tape cable at at least one of a number of longitudinallyspaced locations, at least one branch length of tape cable whose freeend protrudes from the tubular sheath, at least some of the conductorsof the tape cables being electrically connected to insulated terminalleads.
 16. A cable harness as claimed in claim 15, wherein theconnections between the insulated terminal leads and the conductors towhich they are connected are enclosed in a length of heat shrunk tubingof insulating material bonded to the tubular sheath and to theinsulation of the terminal leads to form an effective moisture-tightseal at the end of the sheath.
 17. A cable harness as claimed in claim15, wherein the insulation of each terminal lead carries a distinctivecolor for identifying the function of the cable conductor to which it isconnected.
 18. A cable harness as claimed in claim 15, wherein eachterminal lead is of substantially circular cross-section.
 19. A methodof making a multi-conductor cable which comprises electricallyconnecting to at least one length of tape cable at at least one of anumber of longitudinally spaced locations at least one branch length oftape cable; applying over the length or lengths of tape cable a tubularsheath of heat-shrinkable insulating material; arranging for the freeend of the or each branch length of tape cable to protrude from thesheath; and subjecting the sheathed assembly to sufficient heat to causethe tubular sheath to shrink and grip the length or lengths of tapecable.
 20. A method as claimed in claim 19, wherein the tubular sheathis applied to the length or lengths of tape cable by drawing a singletube of heat-shrinkable insulating material over the assembly andarranging for the or each branch length of tape cable to protrudethrough a slit in the tube.
 21. A method as claimed in claim 19, whereinthe tubular sheath is formed by applying over the length or lengths oftape cable several individual lengths of tube of heat-shrinkableinsulating material, arranged end to end with the ends of adjoiningindividual lengths of tubing overlapping one another, and arranging forthe free end of the or each branch length of taPe cable to protrude frombetween overlapping ends of adjoining lengths of tubing.
 22. A method asclaimed in claim 19, wherein at least two lengths of tape cable arearranged face to face to form an assembly of flattened cross-section andthe or each branch length of tape cable is connected to at least one ofthe lengths of tape cable in such a way that its free end protrudes froma wider side of the sheath.
 23. A method as claimed in claim 19, whereinthe or each branch length of tape cable is arranged to lie substantiallyparallel to the length of tape cable to which it is to be connected andthe branch length is electrically connected thereto adjacent to one endof the branch length.
 24. A method as claimed in claim 23, wherein afterthe branch length has been electrically connected to the length of tapecable it is folded at least partially around the length or lengths oftape cable before it is arranged to extend lengthwise with respect tothe multi-conductor cable.
 25. A method as claimed in claim 19, whereinafter the branch length has been electrically connected to the length oftape cable it is folded adjacent the connection along a line extendingat approximately 45* to the axis of the cable, is wrapped at leastpartially around the length or lengths of tape cable, and is then foldedabout a line substantially parallel to the first fold in such a way thatthe branch length of tape cable extends lengthwise along themulti-conductor cable.
 26. A method as claimed in claim 19, wherein thepart of the or each branch length of tape cable protruding from thesheath has a tube of heat-shrinkable insulating material applied over itbefore heat is applied to the sheath and tube to cause them to shrink.27. A method as claimed in claim 19, wherein a cable harness is formedby electrically connecting an insulated terminal lead to a conductor ofa length of tape cable at a point spaced from the extreme end of theconductor; applying a heat-sensitive adhesive over the end of the tapecable and the overlying insulated terminal lead; applying a length ofheat-shrinkable tubing over the end of the sheath, the connection soformed and the applied adhesive; and applying heat to shrink the tubingand cause the adhesive to activate and form an effective moisture-tightseal at the end of the sheath.
 28. A method of making a multi-conductorcable which comprises electrically connecting to at least one length oftape cable at at least one of a number of longitudinally spacedlocations at least one branch length of tape cable; applying over thelength or lengths of tape cable several individual lengths of tube ofheat-shrinkable insulating material, arranged end to end with the endsof adjoining individual lengths of tubing being overlapped by the endsof a short length of tubing of heat-shrinkable insulating material toform a tubular sheath; arranging for the free ends of the or each branchlength of tape cable to protrude from between overlapping ends ofadjoining lengths of tubing; and subjecting the sheathed assembly tosufficient heat to cause the tubular sheath to shrink and grip thelength or lengths of tape cable.
 29. A method as claimed in claim 28,wherein the overlapping ends of adjoining lengths of tubing are securedtogether by adhesive.
 30. A method as claimed in claim 29, wherein theadhesive is a heat-sensitive adhesive that is activated by the heatapplied to heat shrink the sheath.